Internal Door mechanisms

Does anyone have any instructions from Quara (or anybody else) on how to maintain the door mechanisms in our properties.
We reported two mechanisms failing in our property just after we arrived on 27 May and when we went to office to chase them on 5 June (having heard nothing for a week) we were given a document from Technical Department stating that failure was due to lack of maintenance or misuse. This they were able to state without even entering our property and looking at the mechanisms.

Has anybody else had these door mechanisms fail ? Let us know to assess how big a problem this might be.

Our most used doorlocks got a lilttle difficult after a while. The lock does not open properly because there is a spring that pulls back the plunch when the handle is pressed. If you ease the handle a little and press it again the door will (hopfully) open. If the plunch (or whatever it is called) get stuck the spring is depressed, and can in bad case be damedged. Did you not know that everything in your house has to be maintained every week? Even things you normally look after every 10-15 years but this is just Quara quality and standard answer. The maintaince dokumentation as stated in the contract does not exist at "MI5" or at leaste they will not give it to you.
The solution is tho check that your lock plunch does not press against the side of the plate in the door post. We made the mistake to hang a cloth hanger on the door. This pressed the door down when closed.